[TCML] Largest arc attainable?

[jimlux]

James Shelton wrote:
> Dear All,
> 
> I'm developing a documentary where we are looking to create the largest possible arc of artificial lightning. Using existing systems - what kind of length could I expect to see, and where does such a system exist? So far, I can find Greg Leyh's Electrum, Bill Wysock's 13M and the Cauac Twin Coils, all of them seem to be able to produce an arc around 50ft in length. However, I read that Tesla himself was able to create artificial lightning arc in the order of 130ft - is this still the record?
> 

Aside from various spark generators that have been mentioned (Marx 
generators, Van deGraaff generators, Tesla coils), if you're looking for 
a good visual, but need it longer, or to control the location, consider 
a long exploding wire.  A thin aluminum wire supported where you want 
the "spark" to go works very well, if you put enough energy into it 
quickly enough. See, e.g., http://home.earthlink.net/~jimlux/artlight.htm

There is, also, large sparks made in the course of testing electrical 
transmission equipment.  Perhaps one of the more famous (aside from the 
Siberian 150 meter monster) is the drawn spark at a substation:
http://www.bestofgooglevideo.com/video.php?video=14 (is but one place to 
get it.. I love how the echo of the spark comes back after it quenches)